Electric-heater element.



F. G. CLARK, P. ACKERMAN & E. CANSFIELD.

ELECTRIC HEATER ELEMENT.

APPLICATION FILED JULY 5. 1911.

Patented June 11, 1918..

witness TED STATES ra rnnr cruis FARLEY GRANGER CLARK, PAUL AGKERMAN, AND CHARLES ERNEST CANSFmLD, 0F

TORONTO, ONTARIO, CANADA, ASSIGNORS TO THE TORONTO POWER COMPANY LIMITED, OF TORONTO, ONTARIO, CANADA, A CORPORATION OF ONTARIO.

ELEGTRICrHEATER ELEMENT.

- Specification of Letters Patent.

Application filed July 5, 1917. Serial No. 178,621. I

To all whom it may concern:

Be it known that we, FARLEY GRANGER CLARK, a citizen of the United States of America, PAUL ACKERMAN, a citizen of Switzerland, and GHARLES' ERNEST OANs- FIELD, a subject of the King of Great Britain,

all residing at the city of Tor0nto,- in the county of York and Province of Ontario,

Dominion of Canada, have invented certain conductivity, which will uniformly difiuse,

by conduction, the heat of the resistant to the surface to be heated, the resistant and heat-conducting bed of cement being covered with non-inflammable heat insulation, preferably protected by. a frame of appropriate mechanical strength.

The electric heater element may be employed for the heatin of" various devices,

' and in some cases, suc as tanks, reservoirs :andthe like, it will take an annular form or be arranged as a belt to encompass the device to 'be heated, andin other cases, it will takeother-formg-theshape and dimensions f es";

of whichtwill ,on the purpose for Whichit is employ'fedw i To explain.one-of"ts uses, we have shown anddescribed -it in connection with .a tank throng or range boiler for domestic, urposes:-'

' Figure 1 of the drawings, g a sectional elevation of a tank with two electric'heater elements "Fig. -2, a vertical cross-section one of .the electric heater elements 4 on a; larger-scale. than Fig, 1; and,

yF-igifi, being a horizontal section of 'a presens- 1 form, of heater element?- circulating system of the building in which it is installed, by an inlet pipe 3 and an outlet pipe 4;. Extending into the bottoml and side l of the tank 1, is a by-pass pipe 5, provided with a drain cockfi, and --insorted in the by-pass pipe 5, is a water heater 6, which may be considered as diagrammatic of one of the usual types'mf gas Water heaters or furnace coils, now in use, this by-pass pipe and water heater. representing an-existing installation.

A and B represent two ,electric heater elements located one near the bottom and the Patented June 11,1918.

other near the top of the tank, to indicate the uses of which the invention is capable to obtain certain circulating efiects. For ,instance, the heater element A, placed near the bottom of the tank, will heat the whole of the tank content uniformly, while the heater element B, placed near the upper end of the tank, may, be employed to assist the heater element A in meeting the demands on the tank content, or it may be employed to quickly heat the top part of the tank content only. I

The heater elements A and B in the drawings, to meet local requirements, or 'aheater element or heater elements may 4 be installed between the heater. elements A and B, and the current may be selectively switched through any or all of these elements to meet the variable demands on the tank shown in Fig. 1, and. the heater element radiation losses, the resistant bein pmvided with terminals A to whicht e cir- I cuit conductors may be connected,,these'tera The tank 1, preferably covered with heat insulation 2,'is water mounted on terminal boards A.

may be laced at positions mtejrmediatethose shown v Q st-ingof a mechanism? l 8'0 content. The heater elements A and B,

strong peripheral wall A? and side-boards A of asbestos or other relatively strong noninflaminable insulating material, may be employed to hold the non-inflammable heat insulating material together when necessary.

Each heater element may be applied to the tank or reservoir a) by covering the tank at the place of installation with a layer of heat-conducting cement or other like material A, then wrapping the resistant A around this layer and covering it with another layer of the same cement or plastic material, and then covering the whole with non-inflammable heat insulation A or (b) the heater element may be manufactured in a self-contained form, as shown in Fig. 3, to be clamped as a complete unit ion the tank,

.in which case its inside surface will approximate the shape of the tank surface, and the voids between the tank surface and the heater element will be filled with heatconducting material C, similar to that in which the resistant is embedded. In both constructions, the heater elements may be applied without disturbing the existing connections.

A preferred form of a self-contained heater element suitable for application to standard domestic hotwater tanks, is shown face,

may-be applied to any in Figs.'2 and 3, as comprising two segments, each consisting of a semi-circular wall A, corresponding side plates A, and end plates A, with molded non-inflammable heat-insulating material A, the inside curvature of the frame approximating that of the tank surand the inside surfacecf the molded heat insulation having a recess A in'which is placedthe resistant A and heat-conductmg bed of'cement or plastic material A each semi-circular element having electric k f i i mounted n terminal boards I rlh'ese heater elements may be used on any,

type of tank or reservoir, or other device, and part of the surface thereof where the desired heating effect is required, and maybe ofsuch'shape and dionly to fit the tank surface,

mensions as not but also to produce the most efficient heat-' ing effect.

' elements may In some installations, the electric heater used in 'conjunctio'nwith the water heater 6, being applied, in such cases, direct to the tank, without disturbing the existing connections. 'In other-cases, they may be used without the water heater by-pass dispensed with, as the necessarvwater and I maintained'rinternally,0f the tank by the electric heater elements, which, as in the previous case, are

constituting a frame filled,

pipe 5' in that case being" 'terial of high and applied direct to the tank without disturbing the existing connectio While we have explained one particular use of our invention, we do not desire to limit ourselves to that use, nor to any structural details.

Having thus frilly described the nature of our invention, what we claim as new and desire to secure by Letters Patent, is:

1. An electric heater element comprising a frame consisting of a mechanically-strong peripheral wall and side pieces of non-in flammable insulating material, anon-infla'm mable insulation contained Within the frame, a heat-conducting bed of plastic madielectric strength and comparatively high heat conductivity molded in the inner surface of the heat-insulating material, and an electrical resistantrembedded in the heat-conducting bed.

2. An electric heater element consisting of a self-contained unit comprising an elm:- trical resistant, a heat conducting bed of plastic material of high dielectric strength comparatively high heat conductivity for the resistant, a covering of non-inflammable heat insulation for the resistant and heat conducting bed, and heat conducting material filling the voids between the heatconducting bed and the surface to which the electric heater element is applied.

3. An electric heater element consisting of a self-contained unit comprisingtwo segments, each segment consisting of molded non-ina heat conducting bed of high dielectric-strength and comparatively high heat conductivity inserted in the inner surfaceof the non-inflammable heat insulation, an electrical resistant contained in the heat-conducting bed, terminals for the resistant, and heat-conducting material fillmg the voids between the heat-conducting heater element consisting applied.

the electric sistant contained in the heatconducting bed, terminals for the resistant, and heatconducting material filling the voids between the heat-conducting bed and the surface to' which the electric heater element is electric heater element consisting of a self-contained unit, comprising a frame flammable heat insulation, an electrical reconsisting of a mechanically-strong periphfilling the voids between the heat-conducteral' wall and sidepieces of non-inflammaing bed and the surface to which the elecble insulating material, a, non-inflammable tric heater element is applied.

insulation contained within the frame, a Toronto, June 14th, 1917.

5 heat-conducting bed of plastic material of FARLEY GRANGER CLARK.

high dielectricstrength and comparatively PAUL AOKERMAN. high heat conductivity molded in the inner CHARLES ERNEST GANSFIELD. surface of the heat-insulating material, an Signed in the presence of electrical resistant embedded in theheat-con- CHAs. H. Browns,

10 ducting bed, and heat-conducting material WM. VOLKMANN. 

